A strategic and science-based framework for management of invasive annual grasses in the sagebrush biome

Authors: Boyd, Chad; CREUTZBURG, MEGAN - Oregon State University; KUMAR, ALEXANDER - Us Fish And Wildlife Service; SMITH, JOSEPH - University Of Montana; DOHERTY, KEVIN - Us Fish And Wildlife Service; MEALOR, BRIAN - University Of Wyoming; BRADFORD, JOHN - Us Geological Survey (USGS); CAHILL, MATTHEW - The Nature Conservancy; Copeland, Stella; DUQUETTE, CAMERON - The Nature Conservancy; GARNER, LINDY - Us Fish And Wildlife Service; HOLDREGE, MARTIN - Us Geological Survey (USGS); SPARKLIN, BILL - Us Fish And Wildlife Service; CROSS, TODD - University Of Waterloo

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/8/2024
Publication Date: 10/15/2024
Citation: Boyd, C.S., Creutzburg, M.K., Kumar, A.V., Smith, J.T., Doherty, K.E., Mealor, B.A., Bradford, J.B., Cahill, M., Copeland, S.M., Duquette, C.A., Garner, L., Holdrege, M.C., Sparklin, B., Cross, T.B. 2024. A strategic and science-based framework for management of invasive annual grasses in the sagebrush biome. Rangeland Ecology and Management. 97:61-72. https://doi.org/10.1016/j.rama.2024.08.019.
DOI: https://doi.org/10.1016/j.rama.2024.08.019

Interpretive Summary: Invasive annual grasses (IAGs) represent the most intractable contemporaneous problem impacting sagebrush ecosystems and their continued spread and infill, despite massive conservation effort, threatens a wide suite of values and ecosystem services across the sagebrush biome. We developed framework for defending and growing core sagebrush habitats by identifying biome-wide conservation priorities within IAG prone or impacted areas; that framework stresses maintaining relatively intact plant communities that will be most difficult to restore if impacted by IAGs, improving those IAG-impacted plant communities where IAG treatments are most likely to be successful, and containing IAG infestations where maintenance or improvement is not possible. Our framework indicates that of the 92 million hectares of sagebrush habitat where IAGs exist, only 18, 17.5, and 9 million hectares are Maintain, Improve, or Contain priorities, respectively. These results will empower planning and management entities to strategically plan and implement efforts to ameliorate the IAG problem at biome-wide to local scales.

Technical Abstract: In the last 20 years, the North American sagebrush biome has lost over 500 000 ha of intact and largely intact sagebrush plant communities on an annual basis. Much of this loss has been associated with ex- pansion and infilling of invasive annual grasses (IAGs). These species are highly competitive against native perennial grasses in disturbed environments, and create fuel conditions that increase both the likelihood of fire ignition and the ease of wildfire spread across large landscapes. Given the current rate of IAG expansion in both burned and unburned rangelands, we propose a range-wide paradigm shift from op- portunistic and reactive management, to a framework that spatially prioritizes maintenance of largely intact, uninvaded areas and improvement of invaded habitats in strategic locations. We created a frame- work accompanied by biome-wide priority maps using geospatial overlays that target areas to MAINTAIN large, uninvaded areas as natural resource anchors through activities to prevent IAGs, IMPROVE areas where management success in restoring large, intact landscapes is most likely, and CONTAIN IAG infesta- tions where necessary. We then offer three case studies to illustrate the use of these concepts and map products at multiple scales. Our map products operate at the biome scale using regional data sources and additional data sources will be needed to inform local conservation planning. However, the basic strate- gic management principles of (1) maintaining the intact and uninvaded areas that we can least afford to lose to IAGs, (2) improving areas where we have a reasonable likelihood of restoration success, and (3) containing problems where we must, are timely, relevant, and scalable from the biome to local levels.